Improvement in molds for casting metal door-knobs



C. REBSTOCK & A. HART.

Mold for Casting Metal Door-Knobs.

I ed July 16, 18 72.

Patent UNITED STATES PATENT OFFICE.

CHRISTIAN REBSTOCK, OF BRIDGEPORT, AND ALBERT HART, OF MERIDEN, ASSIGNOR TO C. R. BROTHWELL & CO., OF BRIDGEPORT, CONNECTICUT.

IMPROVEMENT IN MOLDS FOR CASTlNG METAL DOOR-KNOBS.

Specification forming part of Letters Patent No. 129,056, dated July 16, 1872.

To all whom it may concern:

Be it known that we, CHRISTIAN REBsTocK, of Bridgeport, in the county of Fairfield and State of Connecticut, and ALBERT HART, of Meriden, in the county of New Haven and Stateof Connecticut, have invented a new Immovement in Mold for Casting Metal Door- Knobs; and we do hereby declare the followin g, when taken in connection with the accompanying drawing and the letters of reference marked thereon, to be a full, clear, and exact description of the same, and which said drawing constitutes part of this specification, and represents in- Figure 1, a side view Fig. 2, a vertical central section on line on a'; Fig. 3, a top view of the lower portion of the mold; and in Figs. 4 and 5, views of the two parts which form the upper portion.

This invention relates to an improvement in process of casting metal knobs for doors and for similar purposcsthat is, such as are commonly termed bronze knobs, the faces of which are ornamented.

Heretofore this class of knobs have been made by casting in parts, afterward to be soldered together, and these parts have been cast in sand or similar material molded for the purpose, and after casting the ornamentation requires to be chased, making this class of knobs very expensive.

The object of this invention is to produce these knobs complete in a single piece without soldering; and it consists in a mold made in three parts, the base having a cavity formed therein of the form and ornamentation desired for the face of the knob, and into this base the two other parts (divided vertically) are set together, forming a cavity for the neck and back of the knob, and combined with the cavity in the base to shape the exterior of the base complete, the said two parts supporting a core by means of a central rod, which rod is drawn from the mold after casting, leaving an aperture of the size and form required for the door spindle, a channel being formed through the vertical portion of the mold by means of which topour the metal.

A is the base, within which is formed a cavity, B, as seen in Figs. 2 and 3, of the shape and ornamentation required for the face of the knob. On the top of the mold a recess or seat, 0, is formed, into which the two parts D and E of the upper portion of the mold are fitted. These two parts D and E are constructed as seen in Figs. 4 and 5, divided centrally, a cavity, F, formed in each, so that the two parts, when set together into the base, complete the body of the knob, and also, by an extension, G, of the cavity upward, form the neck of the knob and centrallyup through these two portions a recess, H, is formed in each, which, when set together, will permit the insertion of a rod, I, the lower end of the said rod being of the form and size required for the aperture, to be left in the neck of the knob to receive the spindle. Vertically through the mold we form a channel, d, through which to pour the metal into the mold. This channel, extending, as it does, so far above the mold, gives sufficient weight to throw the metal up into the neck and to supply the settling, L' is a core, which is formed of any suitable material, and attached to the end of the spindle, is set into the mold when the parts are put together, and is suspended, by means of the rod, in proper relative position to the mold, that the metal poured into the mold will flow entirely around the core and fill the mold. After the metal is poured, and as soon as set, the rod is withdrawn, and when the metal has been reduced to the required temperature the molds are opened, the knob removed, and the core cleared from the knob, leaving it complete and perfect.

By casting in this manner the ornamentation is made so perfect and sharp that it does not require to be chased or retouched, and thus enables us to produce metal knobs of equal quality at a price much less than has I heretofore been done.

We do not claim suspending the internal core in the mold by a rod, the said rod forming the opening in the neck, as such is not new.

\Ve claim as our invent-ion- 'lhe herein-described mold for casting knobs, consisting of the base A and the verticallydivided upper portion D E fitted to the said base, forming together the cavity of the knob to be cast, and with a vertical rod, I, arranged therein, supporting the core L and having a channel, d, through which to pour the metal, substantially as described.

CHRISTIAN REBSTOOK. ALBERT HART.

Witnesses:

RUDOLPH KOST, HERMANN GENEss. 

